"Amend" has a special meaning with regard to tax returns. Did you already file your 2016 tax return without reporting the business income and expenses? If you have not yet filed, you don't amend your return, you just add the business information before you file. You only amend a return that has already been filed and processed.
When you posted your question you indicated that you are using TurboTax Free Edition. In order to enter business expenses, and show a loss, you will have to upgrade to TurboTax Self-Employed. Since you did not form any business entity, your business is a sole proprietorship and you report it on Schedule C as part of your personal tax return.
If you already filed the return without the business information, and it has not been rejected, go to the following link for instructions to amend a 2016 tax return that you filed with TurboTax Online.
https://ttlc.intuit.com/questions/3402261-how-do-i-amend-my-2016-turbotax-online-return
An amended return has to be filed on a special form, Form 1040X. It cannot be e-filed. You have to print it and file it by mail. It takes the IRS up to 16 weeks to process an amended return.
Don't file the amended return until your first return has been accepted and you have received the original refund.
